Friday, March 22, 2013

Our Baby Universe with Ed Copeland and Planck Satellite


Where do the seeds of structure in our Universe come from, and why does our Universe appear the way it does? In this talk, Ed explores what happened in those earliest moments that lead to the Universe forming itself into what it is today. He also tells us a bit of a story about how the theories were developed, and who the scientists were behind them.Our Baby Universe: Ed Copeland at TEDxUoN



Cosmic microwave background seen by Planck


 The ESA's Planck satellite, dedicated to studying the early universe, was launched on May 2009 and has been surveying the microwave and submillimetre sky since August 2009. In March 2013, ESA and the Planck Collaboration publicly released the initial cosmology products based on the first 15.5 months of Planck operations, along with a set of scientific and technical papers and a web-based explanatory supplement. This paper describes the mission and its performance, and gives an overview of the processing and analysis of the data, the characteristics of the data, the main scientific results, and the science data products and papers in the release. Scientific results include robust support for the standard, six parameter LCDM model of cosmology and improved measurements for the parameters that define this model, including a highly significant deviation from scale invariance of the primordial power spectrum. The Planck values for some of these parameters and others derived from them are significantly different from those previously determined. Several large scale anomalies in the CMB temperature distribution detected earlier by WMAP are confirmed with higher confidence. Planck sets new limits on the number and mass of neutrinos, and has measured gravitational lensing of CMB anisotropies at 25 sigma. Planck finds no evidence for non-Gaussian statistics of the CMB anisotropies. There is some tension between Planck and WMAP results; this is evident in the power spectrum and results for some of the cosmology parameters. In general, Planck results agree well with results from the measurements of baryon acoustic oscillations. Because the analysis of Planck polarization data is not yet as mature as the analysis of temperature data, polarization results are not released. We do, however, illustrate the robust detection of the E-mode polarization signal around CMB hot- and cold-spots. See: Planck 2013 results. I. Overview of products and scientific results

ESA and the Planck Collaboration





Cosmological parameters from 2013 Planck results[18]
 
Parameter Symbol Planck - Best fit
(CMB+lensing)
Planck - 68% limits
(CMB+lensing)
Planck - Best fit
(Planck+WP+highL+BAO)
Planck - 68% limits
(Planck+WP+highL+BAO)
Age of the universe (Ga) t_0 13.784 13.796±0.058 13.7965 13.798±0.037
Hubble's constant ( kmMpc·s ) H_0 68.14 67.9±1.5 67.77 67.80±0.77
Physical baryon density \Omega_b h^2 0.022242 0.02217±0.00033 0.022161 0.02214±0.00024
Physical cold dark matter density \Omega_c h^2 0.11805 0.1186±0.0031 0.11889 0.1187±0.0017
Dark energy density \Omega_\Lambda 0.6964 0.693±0.019 0.6914 0.692±0.010
Density fluctuations at 8h−1 Mpc \sigma_8 0.8285 0.823±0.018 0.8288 0.826±0.012
Scalar spectral index n_s 0.9675 0.9635±0.0094 0.9611 0.9608±0.0054
Reionization optical depth \tau 0.0949 0.089±0.032 0.0952 0.092±0.013
Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.; et al. (Planck Collaboration) (20 March 2013). "Planck 2013 results. I. Overview of products and scientific results". Astronomy & Astrophysics (submitted). arXiv:1303.5062.




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